Kidney stone disease can be influenced by genetic and environmental factors. Social determinants of health (SDOH) are the conditions that shape one’s personal identity and sense of community, which significantly impact their health-related outcomes. Environmental factors, shaped by individuals’ SDOH, play a crucial role in stone risk. Lower socioeconomic status (SES) correlates with recurrent stone disease and worse outcomes.¹ It is thus imperative to consider and address SDOH factors influencing stone formation and treatment.

Financial Toxicity of Stone Disease

Poverty poses challenges for families to afford necessities like healthy food, housing, and health care. Our group recently assessed the financial toxicity (FT) of stone disease and treatment. We surveyed 241 patients using a validated tool to evaluate direct and indirect stone-related costs. Sixty percent of patients experienced at least moderate FT, and 26% faced severe FT from their stone disease. The study also noted the direct correlation between out-of-pocket expenses and FT, stressing the need for urologists to consider patients’ financial barriers and treatment expenses to facilitate informed decision-making.² Likewise, a survey from Ahmad et al utilizing the Wisconsin Quality of Life Questionnaire showed that unemployment and lower income were independently associated with significantly lower health-related quality of life among kidney stone patients.³

Education

Household income influences access to and quality of education, with higher levels of education correlated to better health and prolonged lifespans. Notably, a retrospective study by Bayne et al explored social factors related to advanced kidney stone disease, defined as > 2 cm unilateral kidney stone burden.¹ Their analysis revealed a significant correlation between advanced stone disease and lower education levels (odds ratio [OR] 1.91, CI 1.21-2.99, P = .005). Additionally, patients with lower mean incomes were more prone to advanced stone disease (OR 2.38, CI 1.03-5.50, P = .044). Lower education levels often coincide with reduced health literacy, limiting patients’ ability to make informed decisions. Educational disparities can significantly impact understanding of symptomology and dietary habits, potentially promoting the formation and recurrence of kidney stones.⁴

Neighborhood and Built Environment

The impact of environmental and social factors on kidney stone formation is evident in recent studies. Social distress scores including factors such as poverty levels, housing vacancy, and unemployment rates have been correlated with lower urine potassium (P = .002, β = −0.072) and citrate (P = .001, β = −1.142), speculated to arise from a lower dietary intake of alkali-rich foods such as fruits and vegetables.⁵ Food insecurity is the term used for households with limited access to adequate food due to economic conditions. Another study from our group used the NHANES (National Health and Nutrition Examination Survey) database to show that those with “very low food security” had a 42% increased likelihood of stone disease.⁶ Understanding these connections is crucial for addressing patients’ holistic well-being and guiding medical practitioners in comprehensive care.

Social and Community Context

Race as a social construct is used to categorize people based on physical appearance, social factors, and cultural backgrounds. Multiple studies have evaluated the association between race and ethnicity with kidney stone prevalence. Abufaraj et al analyzed NHANES data from 2007 to 2018, revealing a consistently higher prevalence of kidney stones among non-Hispanic White individuals.⁷ Tasian et al studied patients in South Carolina from 1997 to 2012 and found that elderly White males had the highest annual incidence of nephrolithiasis.⁸ They also reported that the incidence among Black patients increased by 15% every 5 years compared to White patients (incidence rate ratio 1.15, CI 1.14-1.17). While White males exhibit the highest overall incidence, non-White race is independently associated with lower health-related quality of life among kidney stone patients.³ These findings reflect the complexity of differences and disparities in kidney stone-related risk factors.

Health Care Access

Multiple studies reveal that patients of lower SES receive worse acute care for kidney stones. Balthazar et al noted a rising use of noncontrast CT scans from 2006 to 2015, with increased utilization associated with higher household income, private insurance, and urban hospital designation.⁹ Schoenfeld et al underscored gender-based discrepancies in an urban, low-resource population, with women (OR 0.52, CI 0.49-0.76, P = .001) and low SES individuals (OR 0.50, CI 0.27-0.90, P = .02) experiencing delays in diagnostic imaging for nephrolithiasis.¹⁰ Of note, there were no racial differences in treatment identified in this study. Conversely, Berger et al demonstrated racial disparities in pain management among patients presenting to the emergency department with urolithiasis, with White patients receiving higher median opiate doses (20 mg) than Black (−3.3 mg, CI −4.6 to −2.1, P < .01) or Hispanic (−6.0 mg, CI −6.9 to −5.1, P < .01) patients.¹¹ Similarly, Brubaker et al found that Black and Hispanic patients experienced longer delays to surgery, highlighting treatment delays for underinsured and minority individuals.¹²

Conclusion

The development of kidney stone disease is multifactorial, with a complex interplay between genetic, metabolic, environmental, and social factors. It is imperative that physicians consider these factors when developing treatment plans for kidney stone disease. There are special considerations that can be taken for patients with social needs that may decrease FT, increase compliance, and improve outcomes (Table). Employing strategies such as social needs screening and a particular emphasis on shared decision-making that is informed by an understanding of these variables may help to address the disparities in care identified in the literature.

Table. Special Considerations for Patients With Kidney Stones and Social Determinants of Health Barriers